The relationship of periscapular strength on scapular upward rotation in professional baseball pitchers.

CONTEXT Deficiencies in scapular upward rotation and periscapular strength have been associated with various shoulder pathologies and decreased athletic performance. Therefore, proper periscapular strength and concomitant scapular upward rotation are important factors among overhead athletes, such as baseball players. OBJECTIVE To assess the relationships between lower trapezius and serratus anterior strength and the quantity of scapular upward rotation. DESIGN Descriptive study. SETTING Laboratory. PARTICIPANTS 24 professional baseball pitchers. MEASURES Scapular upward rotation was measured at 0 degrees , 60 degrees , 90 degrees , and 120 degrees of humeral elevation. The maximum isometric strength of the lower trapezius and serratus anterior were measured. RESULTS There was a moderate-good positive relationship between lower trapezius strength and scapular upward rotation at 90 degrees (r2 = .56, P = .001) and 120 degrees (r2 = .53, P = .001). The relationships between scapular upward rotation and serratus anterior strength were all poor. CONCLUSION A moderate-good relationship existed between lower trapezius strength and scapular upward rotation.